Cells having pluripotency have been reported, such as embryonic stem cells (ES cells) and induced pluripotent stem cells (iPS cells), wherein the iPS cells can be obtained by introducing an undifferentiated cell-specific gene(s) into somatic cells of animals (U.S. Pat. No. 5,843,780 or WO 2007/069666). Hence, one has drawn attention to therapeutic methods comprising transplanting neural cells, which are obtained by differentiation of pluripotent stem cells, which methods may serve as alternative methods for treating neurodegenerative diseases or nerve injuries. The following methods have been developed as methods for inducing the differentiation of ES cells into neural cells: (1) a method for inducing differentiation by causing embryoid body formation in serum free medium (SFEB method) (Watanabe K, et al. Nat. Neurosci. 8: 288-96, 2005); (2) a method for inducing differentiation by culturing ES cells on stromal cells (SDIA method) (Kawasaki H, et al. Neuron. 28: 31-40, 2000); and (3) a method for adding a drug onto Matrigel and then culturing (Chambers S M, et al. Nat. Biotechnol. 27: 275-80, 2009).
However, there are some problems that undifferentiated cells remain after the induction of the differentiation by these methods, and the use of cytokines in these methods results in very high cost, for example. Accordingly, many small molecule compounds have been developed as cytokine replacements (WO 2008/033408), but which small molecule compounds induce highly efficient differentiation into neural cells remains unknown.